摘要：Objectives . This study identified mutually exclusive groups of men at high and low risk for use of chewing tobacco and for quitting. Methods . Analyses used a national sample of 1340 non-Hispanic Black, 1358 Mexican American, and 1673 non-Hispanic White men, aged 25 to 64, who participated in the National Health and Nutrition Examination Survey III from 1988 to 1994. Signal detection analysis was used to delineate high- and low-risk subgroups; survival analysis was used to estimate hazard curves for comparing age at onset for chewing tobacco use with that for smoking. Results . Rural, lower-income Black and White men had the highest regular use of chewing tobacco (33.3%), followed by rural, higher-income men regardless of race/ethnicity (14.9%). Southern men who began using chewing tobacco during adulthood had the lowest quit rate (22.5%). In sharp contrast to smoking, chewing tobacco showed a continued onset throughout adulthood. Conclusions . Because subgroups of men show highly different chewing tobacco use and quit rates and because age at chewing tobacco onset occurs across the life span, prevention and cessation programs should be specific to different risk groups and distinct from smoking programs. More than 5 million men and women in the United States use chewing tobacco, which contributes to serious diseases of the mouth and heart and several types of cancer. 1– 8 The prevalence of chewing tobacco use varies widely by region and sociodemographic factors. Rates are highest in the South and rural areas, 8 and men use chewing tobacco at 10 times the rate for women. 9 Among men, American Indians/Alaskan natives and Whites have the highest rates of chewing tobacco use: 7.8% and 6.8%, respectively. Black, Hispanic, and Asian and Pacific Islander men use at much lower rates: 3.1%, 1.5%, and 1.2%, respectively. Among women, Blacks and American Indians/Alaskan natives have the highest rates: 2.9% and 1.2%, respectively. White and Hispanic women have the lowest rates: 0.3% and 0.1%, respectively. Asian and Pacific Islander women almost never use chewing tobacco. 9 Chewing tobacco use rates increase as years of education decrease for both men and women. For example, 7.7% of the men with less than a high school education use chewing tobacco compared with 2.5% of the men with a college education or more. 8 Over the last 20 years, prevalence rates for most groups have decreased; only White men aged 18 to 34 showed a higher prevalence rate in 1991 than in 1970. 9 Despite recent trends suggesting that the overall use of chewing tobacco may be stabilizing, 9 the continuing danger is that prevalence rates may not decrease further or that they may increase. The tobacco industry has shown remarkable flexibility in adjusting its marketing strategy to keep tobacco use at high levels. For example, the prevalence of chewing tobacco use among White men aged 18 to 24 increased 5-fold (from 2.2% in 1970 to 10.1% in 1991) during an extensive chewing tobacco advertisement and promotional campaign targeting this specific age group. 10– 12 Furthermore, the tobacco industry and even some researchers have suggested that switching to chewing tobacco may be an acceptable, safer alternative to smoking; this suggestion can only serve to increase its popularity. 13 These concerns underscore the need to identify patterns of use among different sociodemographic groups and those at highest risk. National surveys on the health of Americans, such as the National Health Interview Survey and the Behavioral Risk Factor Survey, regularly report overall prevalence rates of chewing tobacco use. However, these reports rarely present in-depth information about the characteristics of those who have chewed regularly and those who have quit. In the current analyses, we were interested in the relation of multiple sociodemographic factors to chewing and quitting and whether these factors delineated distinct high- and low-risk subgroups. Such delineation can aid in the development of tailored prevention and cessation programs and can help counter the pro-tobacco influences that promote chewing tobacco use. In this study, we used signal detection methodology to identify distinct subgroups of men who had ever used chewing tobacco regularly and who had quit, based on national data collected in the National Health and Nutrition Examination Survey III (NHANES III). In addition, we compared the age at onset for chewing tobacco users and for cigarette smokers to contribute to our understanding of the differences between each form of tobacco use. We focused our study on men because very few women use chewing tobacco. 9
